The technology of receiving sensor signals to detect a crank rotation angle and a cam angle of an engine, calculating the crank rotation angle and the cam angle by an arithmetic processing unit, and controlling the timing of fuel injection and the timing of ignition for each cylinder based on the obtained calculation results has been widely used in an electronic control unit (ECU). The sensor signals are not limited to each single input. For example, some ECUs perform control processing by using information of a plurality of cam angle sensor signals.
Additionally, with regard to the detection of the crank rotation angle and the cam angle, a signal processing circuit available for both of a rotation sensor of the magnetic pickup (MPU) method and that of the magnetoresistive element (MRE) method has been known in the art (see, for example, PTL 1).